1. Field of the Invention
The present invention relates to a beryllium copper alloy containing beryllium (Be), nickel (Ni), and copper (Cu), and a method of manufacturing this beryllium copper alloy.
2. Description of the Related Art
Conventional copper alloys containing beryllium, nickel, and copper (hereinafter referred to as a “beryllium copper alloys”) are widely used for spring materials, relays, terminals, connecters, lead frames, and the like (hereinafter collectively referred to as “lead frames, etc.”). The strength (such as 0.2% proof stress) and the electric conductivity (such as the International Annealed Copper Standard or IACS) of such beryllium copper alloys are required to be desired values or higher.
Beryllium copper alloys in each of which the alloy composition (or mass %) of beryllium and nickel are controlled in pursuit of improvement in strength and in electric conductivity is disclosed (see Journal of the Japan Copper and Brass Research Association, Japan Copper and Brass Association, Vol. 15, pp. 154 left column 6L-17L, for example). Specifically, a beryllium copper alloy with an alloy composition by weight (or mass %) of CuNi2Be0.18 or of CuNi1Be0.25 has an excellent strength by being hardened in age hardening process and an electric conductivity of from 50% to 60% IACS (hereinafter referred to as a first beryllium copper alloy).
A beryllium copper alloy with improved strength and electric conductivity by adding tin (Sn), zirconium (Zr), and titanium (Ti) is also disclosed (see Japanese Unexamined Patent Publication No. 10(1998)-183276, especially claim 1 and Table 5-8). Specifically, a beryllium copper alloy with an alloy composition by weight (or mass %) of CuNi0.4-1.25Be0.15-0.5Zr(and/or Ti)0.06-1.0Sn0-0.25 has a strength of 556-MPa and an electric conductivity of 66% IACS (hereinafter referred to as a second beryllium copper alloy).
Furthermore, a beryllium copper alloy applicable to a relatively large-size member such as a rolling-mill roll is also disclosed (see Japanese Patent Publication No. 3504284, especially claim 1, claim 3, and Table 4, etc.). The method of manufacturing the alloy includes the controlling of the Be/Ni content ratio (hereinafter referred to as “Be/Ni ratio”). Specifically, a beryllium copper alloy with an alloy composition by weight (mass %) of CuNi1.2-2.6Be0.1-0.45 and a Be/Ni ratio of from 5.5 to 7.5 a beryllium copper alloy has a combination of a strength and an electric conductivity of 681 Mpa—68.4% LACS (40.2 m/Ωmm2) or 711 Mpa—68.2% IACS (40.1 m/Ω mm2) (hereinafter referred to as a third beryllium copper alloy).